KR102352953B1 - Adhesive film, optical member comprising the same and optical display apparatus comprising the same - Google Patents

Abstract

The pressure-sensitive adhesive film is formed of a pressure-sensitive adhesive composition containing a (meth)acrylic copolymer and a fluorine-based (meth)acrylate or a pressure-sensitive adhesive composition containing a fluorine-based (meth)acrylic copolymer, and the pressure-sensitive adhesive film has a water contact angle of 110° at 25°C. Provided are an adhesive film having a peel force of 25 gf/inch or more with respect to an adherend having a phosphorus fluorine-based anti-fingerprint layer formed thereon, an optical member including the same, and an optical display device including the same.

Description

Adhesive film, an optical member including the same, and an optical display device including the same

The present invention relates to an adhesive film, an optical member including the same, and an optical display device including the same.

Recently, attention has been focused on flexible displays. The most basic task of the flexible display is to replace all substrates used in the display with films or substrates having flexibility. Among them, the adhesive film provided in the flexible display must also be able to satisfy flexibility by dispersing the stress of each layer or each substrate.

The window film provided in the flexible display is disposed at the outermost part. Therefore, in order to protect the window film from external impact or foreign substances, the protective film for the window film should be laminated to the window film, specifically, the coating layer of the window film. A protective film for a window film and a window film are laminated by an adhesive film. However, it is common for the window film to form an anti-fingerprint layer to protect it from external fingerprints when the flexible display is used. Therefore, there is a need to develop an adhesive film capable of stably securing foldability with high peeling force for each of the anti-fingerprint layer and the protective film for the window film.

Background art of the present invention is disclosed in Korean Patent Application Laid-Open No. 2007-0055363.

An object of the present invention is to provide a pressure-sensitive adhesive film having a high peeling force with respect to an adherend having a fluorine-based anti-fingerprint layer formed on the surface thereof.

Another object of the present invention is to provide an adhesive film that secures stable and good foldability even in a state in which it is adhered to an adherend having a fluorine-based anti-fingerprint layer formed on its surface.

Another object of the present invention is to provide a pressure-sensitive adhesive film that is easily removed upon removal after being adhered to an adherend having a fluorine-based anti-fingerprint layer formed on the surface thereof and has no adhesive residue on the surface of the adherend.

Another object of the present invention is to provide an adhesive film having improved processability by being optically transparent.

One aspect of the present invention is an adhesive film.

1. The pressure-sensitive adhesive film is formed of a pressure-sensitive adhesive composition containing a (meth)acrylic copolymer and a fluorine-based (meth)acrylate or a pressure-sensitive adhesive composition containing a fluorine-based (meth)acrylic copolymer, and the pressure-sensitive adhesive film has a water contact angle at 25° C. The peeling force with respect to the adherend on which the 110° fluorine-based anti-fingerprint layer is formed is 25 gf/inch or more.

2. In 1, the adhesive film may have a peeling force of 25 gf/inch or more for an adherend having an anti-fingerprint layer having a water contact angle of 102° at 25°C.

3. In 1-2, the adhesive film may have a peeling force of 25 gf/inch or more for an adherend having an anti-fingerprint layer having a water contact angle of 95° at 25°C.

4. In 1-3, the pressure-sensitive adhesive film is formed of a pressure-sensitive adhesive composition including the (meth)acrylic copolymer and the fluorine-based (meth)acrylate, and the (meth)acrylic copolymer contains a hydroxyl group (meth)acrylate, an alkyl group It may be formed of a monomer mixture including (meth)acrylate containing (meth)acrylate and (meth)acrylate containing an alkylene glycol group.

5. In 1-4, the fluorine-based (meth)acrylate may be included in an amount of 0.05 parts by weight to 0.5 parts by weight based on 100 parts by weight of the monomer mixture.

6. In 1-5, the alkylene glycol group-containing (meth)acrylate may be included in an amount of 10% to 50% by weight of the monomer mixture.

7. In 1-4, the monomer mixture is 5% to 30% by weight of the hydroxyl group-containing (meth)acrylate, 40% to 80% by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group-containing (meth)acrylate ) It may contain 5% to 50% by weight of acrylate.

8. In 1-7, the fluorine-based (meth) acrylate may include a perfluorinated (perfluorinated) monofunctional (meth) acrylate having an alkyl group having 1 to 10 carbon atoms, substituted with an alkyl group having 1 to 10 carbon atoms. can

9. In 1-8, the fluorine-based (meth)acrylate is at least one of tridecafluorooctyl (meth)acrylate, dodecafluoroheptyl (meth)acrylate, and heptadecafluorodecyl (meth)acrylate may include

10. In 1-9, the monomer mixture may further include (meth)acrylate having an alicyclic group.

11. In 1-10, the monomer mixture contains 5 wt% to 30 wt% of the hydroxyl group-containing (meth)acrylate, 40 wt% to 80 wt% of the alkyl group-containing (meth)acrylate, and ( It may include 5 wt% to 50 wt% of meth)acrylate and 5 wt% to 20 wt% of (meth)acrylate having the alicyclic group.

12. In 1, the pressure-sensitive adhesive film is formed of a pressure-sensitive adhesive composition including the fluorine-based (meth)acrylic copolymer, and the fluorine-based (meth)acrylic copolymer is a hydroxyl group-containing (meth)acrylate, an alkyl group-containing (meth)acrylate , alkylene glycol group-containing (meth) acrylate, may be a copolymer of a monomer mixture containing a fluorine-based (meth) acrylate.

13. In 1, 12, the monomer mixture is 5 to 30 parts by weight of the hydroxyl group-containing (meth)acrylate, 40 to 80 parts by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group-containing ( 5 to 50 parts by weight of meth)acrylate, and 0.05 to 0.5 parts by weight of the fluorine-based (meth)acrylate.

14. In 1,12-13, the fluorine-based (meth) acrylate is a monofunctional (meth) acrylate having an alkyl group having 1 to 10 carbon atoms, substituted with a perfluorinated alkyl group having 1 to 10 carbon atoms may include

15. In 1,12-14, the fluorine-based (meth)acrylate is tridecafluorooctyl (meth)acrylate, dodecafluoroheptyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate It may include one or more types.

16. In 1,12-15, the monomer mixture may further include (meth)acrylate having an alicyclic group.

17. In 1,12-16, the monomer mixture is 5 parts by weight to 30 parts by weight of the hydroxyl group-containing (meth)acrylate, 40 parts by weight to 80 parts by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group 5 parts by weight to 50 parts by weight of the (meth)acrylate containing, 0.05 parts by weight to 0.5 parts by weight of the fluorine-based (meth)acrylate, 5 parts by weight to 20 parts by weight of the (meth)acrylate having an alicyclic group. .

18. In 1-17, the adhesive film may have a modulus ratio of -20°C modulus: 80°C modulus of 5:1 to 20:1.

The optical member of the present invention includes an adhesive film and an optical film laminated on at least one surface of the adhesive film, and the adhesive film includes the adhesive film of the present invention.

The optical display device of the present invention includes the adhesive film of the present invention.

The present invention provides a pressure-sensitive adhesive film having a high peeling force with respect to an adherend having a fluorine-based anti-fingerprint layer formed on the surface thereof.

The present invention provides an adhesive film that secures stable and good foldability even in a state in which it is adhered to an adherend having a fluorine-based anti-fingerprint layer formed on its surface.

The present invention provides a pressure-sensitive adhesive film that is easily removed upon removal after being adhered to an adherend having a fluorine-based anti-fingerprint layer formed on the surface thereof and has no adhesive residue on the surface of the adherend.

The present invention provides an adhesive film with improved processability by being optically transparent.

1 is a cross-sectional view of an optical member according to an embodiment of the present invention.

With reference to the accompanying drawings, the following examples will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. The length and size of each component in the drawings are for explaining the present invention, and the present invention is not limited to the length and size of each component described in the drawings.

In this specification, 'upper' and 'lower' are defined based on the drawings, and 'upper' may be changed to 'lower' and 'lower' to 'upper' depending on the viewing angle.

In the present specification, '(meth)acryl' may mean acryl and/or methacrylic.

As used herein, the 'copolymer' may include an oligomer, a polymer, or a resin.

In this specification, 'modulus' is a storage modulus (G').

In the present specification, the 'glass transition temperature of a homopolymer' may mean a glass transition temperature (Tg) measured using DSC Discovery of TA Instruments for a homopolymer of a measurement target monomer. Specifically, after raising the temperature to 180 °C at a rate of 20 °C/min with respect to the homopolymer of the monomer to be measured, cooling it slowly to -100 °C, and then raising the temperature to 100 °C at a rate of 10 °C/min. After obtaining data on the endothermic transition curve, the inflection point of the endothermic transition curve may be determined as the glass transition temperature.

In the present specification, the 'water contact angle' for the anti-fingerprint layer or base film is a method of measuring the angle between the anti-fingerprint layer or base film and the water droplet by dropping one drop of water on the anti-fingerprint layer or base film at 25° C. It may mean a measured value.

As used herein, the term 'substrate film' refers to a film used as a substrate to which the pressure-sensitive adhesive composition is applied when forming the pressure-sensitive adhesive film. Although not particularly limited, the base film may be a thermoplastic polyurethane (TPU) film or a polyethylene terephthalate (PET) film.

In the present specification, when describing a numerical range, 'X to Y' means X or more and Y or less (X≤ and ≤Y).

The inventor of the present invention is a pressure-sensitive adhesive composition comprising a (meth)acrylic copolymer formed from a monomer mixture detailed below and a fluorine-based (meth)acrylate described in detail below or a pressure-sensitive adhesive composition comprising a fluorine-based (meth)acrylic copolymer described in detail below. By forming the pressure-sensitive adhesive film, the fluorine-based anti-fingerprint layer specifically has a high peeling force with respect to an adherend having a fluorine-based anti-fingerprint layer formed on the surface, and stable and good foldability can be ensured even when the adherend is adhered to the surface. After being adhered to the adherend on which the fluorine-based anti-fingerprint layer is formed, the present invention was completed after confirming that it can be easily removed and there is no adhesive residue on the surface of the adherend.

The peel force is measured as the peel force when the laminate of the base film and the pressure-sensitive adhesive film is attached to an adherend having a fluorine-based anti-fingerprint layer formed on the surface through the pressure-sensitive adhesive film and the laminate is peeled from the anti-fingerprint layer. . Accordingly, the pressure-sensitive adhesive film of the present invention has a high peeling force with respect to each of the base film and the anti-fingerprint layer. The 'base film' may be a thermoplastic polyurethane (TPU) film or a polyethylene terephthalate (PET) film.

Hereinafter, an adhesive film according to a first embodiment of the present invention will be described.

The pressure-sensitive adhesive film is formed of a pressure-sensitive adhesive composition comprising a (meth)acrylic copolymer and a fluorine-based (meth)acrylate, and the pressure-sensitive adhesive film has a water contact angle of 110° at 25°C. It can be more than 25 gf/inch. In the peeling force range, the laminate of the pressure-sensitive adhesive film and the base film may be adhered to the adherend having the fluorine-based anti-fingerprint layer formed thereon with a high peel force, thereby sufficiently protecting the adherend.

For example, the pressure-sensitive adhesive film may have a peel force of 25 gf/inch to 35 gf/inch, or 25 gf/inch to 32 gf/inch with respect to an adherend having a fluorine-based anti-fingerprint layer having a water contact angle of 110° at 25°C. Within the above range, it is possible to sufficiently protect an adherend having a fluorine-based anti-fingerprint layer formed on the surface thereof, and it may be easy to manufacture an adhesive film, and release of the adhesive film from the adherend may be easy.

In one embodiment, the pressure-sensitive adhesive film has a water contact angle of 100° to 109° at 25° C., specifically, a peel force of 80 gf/inch or more, for example, 90 gf/inch or more, with respect to an adherend with an anti-fingerprint layer formed at 102°, It can be 80 gf/inch to 130 gf/inch, 85 gf/inch to 120 gf/inch. Within the above range, it is possible to sufficiently protect an adherend having a fluorine-based anti-fingerprint layer formed on the surface thereof, and it may be easy to manufacture an adhesive film, and release of the adhesive film from the adherend may be easy.

In another embodiment, the pressure-sensitive adhesive film has a peeling force of 400 gf/inch or more to an adherend formed with an anti-fingerprint layer having a water contact angle of 95° at 25° C., for example, 400 gf/inch to 500 gf/inch, 420 gf/inch to 460 gf This can be /inch. Within the above range, it is possible to sufficiently protect an adherend having a fluorine-based anti-fingerprint layer formed on the surface thereof, and it may be easy to manufacture an adhesive film, and release of the adhesive film from the adherend may be easy.

The 'adherent having an anti-fingerprint layer formed on the surface' is a laminate in which an anti-fingerprint layer is formed on one surface of a substrate of the adherend. The 'substrate of the adherend' may be a glass plate, a hard coating layer, a polymer film, or a laminate thereof, but is not limited thereto. The 'fingerprint resistant layer' is a layer formed on the substrate of the adherend to prevent fingerprints from being formed when touched by hand, and may be formed of a fluorine-based material.

The water contact angle at 25° C. of the 'fingerprint resistant layer' may be adjusted by adjusting the type of fluorine-based material in the anti-fingerprint layer, the content of the fluorine-based material in the anti-fingerprint layer, and the like. This is known to those skilled in the art.

The pressure-sensitive adhesive film may be formed of a pressure-sensitive adhesive composition including a (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group and an alkyl group, and a fluorine-based (meth)acrylate.

The (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group and an alkyl group is a monomer mixture comprising a hydroxyl group-containing (meth)acrylate, an alkyl group-containing (meth)acrylate and an alkylene glycol group-containing (meth)acrylate. can be formed. The (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group and an alkyl group may be a fluorine-free non-fluorine-based (meth)acrylic copolymer.

The (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group and an alkyl group may have a glass transition temperature of -100°C to 10°C, specifically -70°C to 0°C. In the above range, the pressure-sensitive adhesive film has an effect of having excellent adhesion and reliability in a wide temperature range.

The (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group and an alkyl group may have a refractive index of 1.35 to 1.70, specifically 1.40 to 1.60. Within the above range, optical transparency may be maintained when laminated with other optical films.

The hydroxyl group-containing (meth)acrylate may provide peel strength of the pressure-sensitive adhesive film.

In one embodiment, the hydroxyl group-containing (meth)acrylate may be a (meth)acrylate having 1 to 10 carbon atoms and containing one or more hydroxyl groups. For example, the hydroxyl group-containing (meth)acrylate is a non-fluorine-based (meth)acrylate that does not contain fluorine, and includes 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2 - May include at least one of hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate However, it is not limited thereto. Preferably, the hydroxyl group-containing (meth)acrylate may be 4-hydroxybutyl (meth)acrylate.

The hydroxyl group-containing (meth)acrylate may have a glass transition temperature of 0°C to -70°C, preferably -10°C to -60°C, more preferably -10°C to -50°C of the homopolymer. In the above range, there may be an effect of increasing the peel strength and bending reliability of the adhesive film.

The hydroxyl group-containing (meth)acrylate is 5% to 40% by weight of the monomer mixture, for example, 5% to 30% by weight, 5% to 20% by weight, 5% to 15% by weight, 8% by weight. It may be included in an amount of to 12% by weight. In the above range, peel strength and durability reliability of the pressure-sensitive adhesive film may be further improved.

The alkyl group-containing (meth)acrylate may form a matrix of the adhesive film.

In one embodiment, the alkyl group-containing (meth)acrylate may be a non-alkylene glycol-based (meth)acrylate that does not contain an alkylene glycol group. The alkyl group-containing (meth)acrylate may be a non-fluorine-based (meth)acrylate that does not contain fluorine. The alkyl group-containing (meth)acrylate may be an unsubstituted linear or branched, C1-C10 alkyl group-containing (meth)acrylate. For example, (meth)acrylate containing an alkyl group is 2-ethylhexyl (meth)acrylate, n-butyl (meth)acrylate, isooctyl (meth)acrylate, propyl (meth)acrylate, t-butyl ( Meth) acrylate, iso-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl at least one of (meth)acrylates, preferably at least one of 2-ethylhexyl (meth)acrylate, n-butyl (meth)acrylate, isooctyl (meth)acrylate, more preferably 2-ethylhexyl It can be a (meth)acrylate.

The alkyl group-containing (meth)acrylate may have a glass transition temperature of -20°C to -80°C, specifically -40°C to -80°C, of the homopolymer. In the above range, the bending reliability of the adhesive film may be good at low temperature and high temperature and high humidity.

The alkyl group-containing (meth)acrylate is 30 wt% to 85 wt% of the monomer mixture, preferably 40 wt% to 80 wt%, 45 wt% to 80 wt%, 50 wt% to 85 wt%, 50 wt% to 80% by weight, 60% to 80% by weight may be included. In the above range, the bending reliability of the adhesive film may be good at low temperature and high temperature and high humidity.

The (meth)acrylate containing an alkylene glycol group can lower the modulus of the adhesive film by containing an alkylene glycol group, so that the adhesive film has excellent foldability. In the present specification, "alkylene glycol group" means (alkylene-O- having 2 to 4 carbon atoms).

The (meth)acrylate containing an alkylene glycol group has a glass transition temperature of -55°C to -90°C, preferably -60°C to -90°C, more preferably -60°C to -75°C of the homopolymer. can In the above range, it is possible to lower the modulus at a low temperature of the pressure-sensitive adhesive film and improve the foldability of the pressure-sensitive adhesive film at a low temperature. The alkylene glycol group-containing (meth)acrylate is an ethylene oxide group (-CH ₂ CH ₂ O-) or a propylene oxide group (-CH ₂ CH ₂ CH ₂ O-), preferably a monofunctional acrylic having an ethylene oxide group. rate may be included.

The alkylene glycol group-containing (meth)acrylate is, for example, methoxy polyethylene glycol (meth) acrylate containing 6 mol to 13 mol of ethylene glycol, and ethylhexyl polyethylene glycol (meth) containing 2 mol to 10 mol of ethylene glycol. ) acrylate, and may include at least one of octyl polyethylene glycol (meth) acrylate. Preferably, the alkylene glycol group-containing (meth)acrylate is at least one of ethylhexyldiethylene glycol (meth)acrylate, ethylhexyltriethylene glycol (meth)acrylate, and octyldiethylene glycol (meth)acrylate. may include

The alkylene glycol group-containing (meth)acrylate is 2% to 60% by weight of the monomer mixture, preferably 5% to 50% by weight, 5% to 35% by weight, 10% to 50% by weight, More preferably, it may be included in an amount of 10 wt% to 40 wt%, 2 wt% to 15 wt%, and 5 wt% to 15 wt%. In the above range, it is possible to ensure stable and good foldability even in a state in which the pressure-sensitive adhesive film is adhered to the adherend with the anti-fingerprint layer formed thereon.

The monomer mixture for the (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group and an alkyl group is a hydroxyl group-containing (meth)acrylate, an alkyl group-containing (meth)acrylate, and an alkylene glycol group-containing (meth)acrylate in addition to It may further include a copolymerizable monomer. The copolymerizable monomer may be included in the (meth)acrylic copolymer to provide an additional effect to the adhesive film. The copolymerizable monomer is a monomer different from the above-mentioned hydroxyl group-containing (meth)acrylate, alkyl group-containing (meth)acrylate, and alkylene glycol group-containing (meth)acrylate, a monomer having an amine group, a monomer having an alkoxy group, a phosphoric acid group may include at least one of a monomer having a sulfonic acid group, a monomer having a phenyl group, a monomer having a silane group, a monomer having a carboxylic acid group, and an amide group-containing monomer.

The monomer having an amine group is monomethylaminoethyl acrylate, monoethylaminoethyl acrylate, monomethylaminopropyl acrylate, monoethylaminopropyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, N-tert- It may be an amine group-containing acrylic monomer such as butylaminoethyl acrylate or acryloxyethyltrimethylammonium chloride acrylate, but is not limited thereto.

Monomers having an alkoxy group include 2-methoxyethyl acrylate, 2-methoxypropyl acrylate, 2-ethoxypropyl acrylate, 2-butoxypropyl acrylate, 2-methoxypentyl acrylate, 2-ethoxypentyl acrylate, 2-butoxyhexyl acrylate, 3-methoxypentyl acrylate, 3-ethoxypentyl acrylate, 3-butoxyhexyl acrylate, but is not limited thereto.

The monomer having a phosphoric acid group may be an acrylic monomer having a phosphoric acid group, such as 2-methacryloyloxyethyldiphenyl phosphate acrylate, trimethacryloyloxyethyl phosphate acrylate, and triacryloyloxyethyl phosphate acrylate. , but is not limited thereto.

The monomer having a sulfonic acid group may be an acrylic monomer having a sulfonic acid group, such as sodium sulfopropyl acrylate, sodium 2-sulfoethyl acrylate, sodium 2-acrylamido-2-methylpropanesulfonate, but is not limited thereto. it is not

The monomer having a phenyl group may be an acrylic vinyl monomer having a phenyl group, such as p-tert-butylphenyl acrylate, o-biphenyl acrylate, and phenoxyethyl acrylate, but is not limited thereto.

Monomers having a silane group include 2-acetoacetoxyethyl acrylate, vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tris (2-methoxyethyl) silane, vinyl triacetoxysilane, acryloyloxypropyl trime It may be a vinyl monomer having a silane group such as oxysilane, but is not limited thereto.

The monomer having a carboxylic acid group may be acrylic acid, 2-carboxyethyl acrylate, 3-carboxypropyl acrylate, 4-carboxybutyl acrylate, itaconic acid, crotonic acid, maleic acid, fumaric acid and maleic anhydride, but is not limited thereto. it is not going to be

Amide group-containing monomers include acrylamide, N-methylacrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N,N-methylenebisacrylamide, N-hydroxyethylacrylamide, N,N- It may be diethylacrylamide, etc., but is not limited thereto.

The copolymerizable monomer may be included in an amount of 30 wt% or less, preferably 0 wt% to 30 wt% of the monomer mixture. It can be used to control adhesion with an adherend and to have optical properties.

In one embodiment, 5 wt% to 30 wt% of the hydroxyl group-containing (meth)acrylate, 40 wt% to 80 wt% of the alkyl group-containing (meth)acrylate, 5 wt% of the alkylene glycol group-containing (meth)acrylate % to 50% by weight. Within the above range, there may be effects of securing peeling force to the adherend, providing good foldability, providing excellent durability, and leaving no residue upon removal from the adherend.

In one embodiment, the monomer mixture is 5 wt% to 15 wt% of a hydroxyl group-containing (meth)acrylate, preferably 8 wt% to 12 wt%, and 50 wt% to 80 wt% of an alkyl group-containing (meth)acrylate is 60 wt% to 80 wt%, alkylene glycol group-containing (meth)acrylate 5 wt% to 35 wt% It may include 5 wt% to 15 wt%.

In one embodiment, the pressure-sensitive adhesive composition may include a (meth)acrylic copolymer prepared from a monomer mixture for a (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group and an alkyl group.

In another embodiment, the pressure-sensitive adhesive composition includes a (meth)acrylic copolymer ((meth)acrylic prepolymer) prepared from a monomer mixture for a (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group and an alkyl group and the remainder of the monomer You may.

The (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group, and an alkyl group may be prepared by adding at least one of a photopolymerization initiator and a thermal polymerization initiator to the monomer mixture and then polymerization in a conventional manner.

The fluorine-based (meth)acrylate may have a peeling force of 25 gf/inch or more with respect to an adherend in which the adhesive film has a fluorine-based anti-fingerprint layer having a water contact angle of 110° at 25°C. Fluorine-based (meth)acrylate contains a (meth)acrylate group in addition to fluorine, thereby crosslinking with the (meth)acrylic copolymer, thereby increasing the bonding strength with the (meth)acrylic copolymer and providing high peel strength for the fingerprint layer. It can be stably maintained, and when the adhesive film is released from the adherend, there is no adhesive residue on the surface of the adherend. An adhesive film formed from a pressure-sensitive adhesive composition containing a fluorine-based compound without a (meth)acrylate group instead of a fluorine-based (meth)acrylate is difficult to stably maintain a high peeling force to an adherend, and has no bonding site for dispersibility and surface quality. As it remains, there is a problem such as being transferred to the adherend or defective in staining.

The fluorine-based (meth)acrylate may include a (meth)acrylate compound having a (meth)acrylate group and an aliphatic hydrocarbon group containing fluorine or an aromatic hydrocarbon group containing fluorine.

In one embodiment, the fluorine-based (meth)acrylate may be a monofunctional (meth)acrylate having one or more, for example, 1 to 21 fluorine-substituted C1-C10 alkyl groups. Preferably, the fluorine-based (meth)acrylate may be a monofunctional (meth)acrylate having one or more, for example, 1 to 21 fluorine-substituted alkyl groups having 5 to 10 carbon atoms.

In another embodiment, the fluorine-based (meth)acrylate may be a monofunctional (meth)acrylate having an alkyl group having 1 to 10 carbon atoms, substituted with a perfluorinated alkyl group having 1 to 10 carbon atoms. Preferably, the fluorine-based (meth)acrylate may be a monofunctional (meth)acrylate having an alkyl group having 1 to 10 carbon atoms substituted with a perfluorinated alkyl group having 1 to 10 carbon atoms.

The 'perfluorinated alkyl group having 1 to 10 carbon atoms' refers to an alkyl group in which all hydrogens bonded to carbon in the alkyl group having 1 to 10 carbon atoms are substituted with fluorine. For example, the perfluorinated alkyl group having 1 to 10 carbon atoms is *-CF ₃ , *-CF ₂ CF ₃ , *-(CF ₂ ) ₂ CF ₃ , *-(CF ₂ ) ₃ CF ₃ , *- (CF ₂ ) ₄ CF ₃ , *-(CF ₂ ) ₅ CF ₃ , *-(CF ₂ ) ₆ CF ₃ , *-(CF ₂ ) ₇ CF ₃ , *-(CF ₂ ) ₈ CF ₃ or *- (CF ₂ ) ₉ CF ₃ (* is a linking site), but is not limited thereto.

For example, fluorine-based (meth)acrylate is a perfluorinated fluorine-based (meth)acrylate, such as tridecafluorooctyl (meth)acrylate, dodecafluoroheptyl (meth)acrylate, heptadecafluorodecyl ( It may include one or more of meth)acrylates. Preferably, the fluorine-based (meth)acrylate may be tridecafluorooctyl (meth)acrylate.

The fluorine-based (meth)acrylate may be included in an amount of 0.05 to 0.5 parts by weight based on 100 parts by weight of the monomer mixture or the (meth)acrylic copolymer. In the above range, the pressure-sensitive adhesive film has a peel force of 25 gf/inch or more for an adherend having a fluorine-based anti-fingerprint layer formed at a water contact angle of 110° at 25° C. By maintaining the modulus detailed below at -20 °C, 25 °C and 80 °C, the foldability of the adhesive film can be secured in a wide temperature range, and there is no residue on the surface of the adherend when the adhesive film is released. Preferably, the fluorine-based (meth)acrylate may be included in an amount of 0.1 to 0.5 parts by weight based on 100 parts by weight of the monomer mixture or the (meth)acrylic copolymer.

The pressure-sensitive adhesive composition may further include an initiator. The initiator may cure the pressure-sensitive adhesive composition to form a pressure-sensitive adhesive film, or polymerize the monomer mixture in the pressure-sensitive adhesive composition to form a (meth)acrylic copolymer having the alkylene glycol group, hydroxyl group and alkyl group.

The initiator may include at least one of a photopolymerization initiator and a thermal polymerization initiator. Any photoinitiator may be used as long as it can induce a polymerization reaction of the radically polymerizable compound described below in a curing process by light irradiation or the like. For example, a benzoin-based, hydroxy ketone-based, aminoketone-based or phosphine oxide-based photoinitiator may be used. As the thermal polymerization initiator, for example, a conventional initiator such as an azo-based compound, a peroxide-based compound, or a redox-based compound may be used.

The initiator may be included in an amount of 0.0001 parts by weight to 5 parts by weight, specifically 0.001 parts by weight to 3 parts by weight, more specifically 0.001 parts by weight to 1 part by weight based on 100 parts by weight of the monomer mixture or the (meth)acrylic copolymer. In the above range, the curing reaction may proceed completely, and a residual amount of the initiator may remain to prevent deterioration of the light transmittance of the pressure-sensitive adhesive film, and may also reduce the generation of bubbles and have excellent reactivity.

The pressure-sensitive adhesive composition may further include a crosslinking agent. The crosslinking agent may increase the degree of crosslinking of the pressure-sensitive adhesive composition to increase the mechanical strength of the pressure-sensitive adhesive film.

The crosslinking agent may include a polyfunctional (meth)acrylate that can be cured with an active energy ray. For example, the crosslinking agent is 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentylglycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, Neopentyl glycol adipate di(meth)acrylate, dicyclofentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified di(meth)acrylate, di(meth) ) Acryloxyethyl isocyanurate, allylated cyclohexyl di(meth)acrylate, tricyclodecanedimethanol (meth)acrylate, dimethylol dicyclopentanedi(meth)acrylate, ethylene oxide-modified hexahydrophthalic acid Di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, neopentyl glycol modified trimethyl propane di (meth) acrylate, adamantane (adamantane) di (meth) acrylate or 9,9-bis [ bifunctional acrylates such as 4-(2-acryloyloxyethoxy)phenyl]fluorene; Trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide trifunctional acrylates such as modified trimethylolpropane tri(meth)acrylate, trifunctional urethane (meth)acrylate, or tris(meth)acryloxyethyl isocyanurate; tetrafunctional acrylates such as diglycerol tetra(meth)acrylate or pentaerythritol tetra(meth)acrylate; 5-functional acrylates, such as dipentaerythritol penta (meth)acrylate; And dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (ex. isocyanate monomer and trimethylolpropane tri (meth) acrylate and hexafunctional acrylates such as reactants, but is not limited thereto.

The crosslinking agent may be included in an amount of 0.001 parts by weight to 5 parts by weight, specifically 0.003 parts by weight to 3 parts by weight, specifically 0.005 parts by weight to 1 part by weight based on 100 parts by weight of the monomer mixture or the (meth)acrylic copolymer. In the above range, there is an effect of excellent peeling force and increased reliability.

The pressure-sensitive adhesive composition may further include an additive. The additives may include conventional additives known to those skilled in the art to be included in the pressure-sensitive adhesive composition. For example, the additive may include, but is not limited to, one or more of a pigment, an ultraviolet absorber, a leveling agent, and an antistatic agent.

The adhesive film may have a modulus of 150 kPa or less at -20°C. In the above range, the flexibility of the pressure-sensitive adhesive film at a low temperature may be excellent, and thus the bending reliability at a low temperature may be excellent. The adhesive film may have a modulus of preferably 50 kPa to 150 kPa, more preferably 80 kPa to 150 kPa, and most preferably 100 kPa to 150 kPa at -20°C.

The adhesive film may have a modulus of 100 kPa or less at 25°C. In the above range, the flexibility of the pressure-sensitive adhesive film at room temperature may be good, and thus the bending reliability at room temperature may be excellent. The pressure-sensitive adhesive film may preferably have a modulus of 1 kPa to 100 kPa, more preferably 10 kPa to 70 kPa, and most preferably 10 kPa to 50 kPa at 25°C.

The adhesive film may have a modulus of 100 kPa or less at 80°C. In the above range, the flexibility of the pressure-sensitive adhesive film at a high temperature may be excellent, and thus the bending reliability at room temperature may be excellent. The adhesive film may have a modulus of preferably 1 kPa to 100 kPa, more preferably 10 kPa to 50 kPa, and most preferably 10 kPa to 30 kPa at 80°C.

The adhesive film may have a modulus ratio of -20°C modulus: 80°C modulus of 5:1 to 20:1, preferably 5:1 to 15:1, more preferably 5:1 to 10:1. In the above range, the foldability can be stably secured in a wide temperature range between low and high temperatures, and the peeling force of the present invention described above can be easily reached.

The adhesive film may have a haze of 2% or less, specifically 0.1% to 1%, and a total light transmittance of 90% or more, specifically 95% to 99% in the visible light region (eg, wavelength 380nm to 780nm). In the above range, the optical transparency is good, so that it can be used in an optical display device.

The pressure-sensitive adhesive film may have a thickness of 10 μm to 300 μm, specifically 10 μm to 150 μm, and more specifically 10 μm to 50 μm. Within the above range, it can be used in an optical display device.

In one embodiment, the adhesive film may not include one or more of inorganic nanoparticles and organic nanoparticles.

Hereinafter, an adhesive film according to a second embodiment of the present invention will be described.

The pressure-sensitive adhesive film is formed of a pressure-sensitive adhesive composition containing a (meth)acrylic copolymer and a fluorine-based (meth)acrylate, and the pressure-sensitive adhesive film has an anti-fingerprint layer having a water contact angle of 110° at 25°C on the surface of the adhesive. This can be more than 25 gf/inch. The (meth)acrylic copolymer includes a (meth)acrylic copolymer having an alkylene glycol group, a hydroxyl group, an alkyl group, and an alicyclic group. The (meth)acrylic copolymer is substantially the same as the pressure-sensitive adhesive film according to an embodiment of the present invention, except that it further has an alicyclic group.

The (meth)acrylic copolymer is from a monomer mixture comprising a hydroxyl group-containing (meth)acrylate, an alkyl group-containing (meth)acrylate, an alkylene glycol group-containing (meth)acrylate, and an alicyclic group-containing (meth)acrylate can be formed. The (meth)acrylate having an alicyclic group may increase the modulus of the adhesive film and increase the peeling force by providing a cyclic functional group to the (meth)acrylic copolymer. The "alicyclic group" refers to a cyclic aliphatic hydrocarbon group consisting of only carbon and hydrogen without a hetero element.

The (meth)acrylate having an alicyclic group may include at least one of isobornyl (meth)acrylate, bornyl (meth)acrylate, and cyclohexyl (meth)acrylate. Preferably, the (meth)acrylate having an alicyclic group may be isobornyl (meth)acrylate.

Preferably, the (meth)acrylate having an alicyclic group may be a (meth)acrylate having a glass transition temperature of 90°C or higher, for example, 90°C to 120°C of the homopolymer. In the above range, it is possible to obtain the effect of increasing the peel force and the modulus of the pressure-sensitive adhesive film and secure the stable foldability of the pressure-sensitive adhesive film.

The (meth)acrylate having an alicyclic group may be included in an amount of 5 wt% to 20 wt%, preferably 7 wt% to 15 wt% of the monomer mixture. In the above range, it is possible to obtain the effect of increasing the peel force and the modulus of the pressure-sensitive adhesive film and secure the stable foldability of the pressure-sensitive adhesive film.

In one embodiment, the monomer mixture is 5% to 30% by weight of the hydroxyl group-containing (meth)acrylate, 40% to 80% by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group-containing (meth) It may include 5 wt% to 50 wt% of an acrylate and 5 wt% to 20 wt% of a (meth)acrylate having the alicyclic group. In the above range, there may be an effect of providing an adhesive film having an appropriate peeling force to the adherend, good foldability, durability, and no residue upon removal from the adherend.

In one embodiment, the monomer mixture is 5 wt% to 15 wt% of a hydroxyl group-containing (meth)acrylate, preferably 8 wt% to 12 wt%, and 50 wt% to 80 wt% of an alkyl group-containing (meth)acrylate is 60 wt% to 80 wt%, 5 wt% to 35 wt% of (meth)acrylate containing an alkylene glycol group, preferably 5 wt% to 12 wt%, and 5 wt% to (meth)acrylate having an alicyclic group 20% by weight, preferably 7% to 15% by weight.

In one embodiment, the adhesive film may not include one or more of inorganic nanoparticles and organic nanoparticles.

Hereinafter, an adhesive film according to a third embodiment of the present invention will be described.

The pressure-sensitive adhesive film according to this embodiment is formed of a pressure-sensitive adhesive composition containing a fluorine-based (meth)acrylic copolymer, and the pressure-sensitive adhesive film has a peeling force of 25 gf for an adherend formed with a fluorine-based anti-fingerprint layer having a water contact angle of 110° at 25° C. It can be more than /inch.

The pressure-sensitive adhesive film can secure substantially the same peel force, modulus, and the like as the pressure-sensitive adhesive film of the first embodiment.

The fluorine-based (meth)acrylic copolymer may include a (meth)acrylic copolymer containing fluorine and having an alkyl group, a hydroxyl group, and an alkylene glycol group. In one embodiment, the fluorine-based (meth)acrylic copolymer is a (meth)acrylic-based copolymer having an alkyl group containing fluorine, an alkyl group not containing fluorine, an alkyl group having a hydroxyl group not containing fluorine, and an alkylene glycol group not containing fluorine. copolymers may be included.

The fluorine-based (meth)acrylic copolymer may have a glass transition temperature of -100°C to 10°C, specifically -70°C to 0°C. In the above range, the pressure-sensitive adhesive film has an effect of having excellent adhesion and reliability in a wide temperature range.

The fluorine-based (meth)acrylic copolymer may have a refractive index of 1.35 to 1.70, specifically 1.40 to 1.60. Within the above range, optical transparency may be maintained when laminated with other optical films.

The fluorine-based (meth)acrylic copolymer is a copolymer of a monomer mixture containing a hydroxyl group-containing (meth)acrylate, an alkyl group-containing (meth)acrylate, an alkylene glycol group-containing (meth)acrylate, and a fluorine-based (meth)acrylate can The hydroxyl group-containing (meth)acrylate, the alkyl group-containing (meth)acrylate, the alkylene glycol group-containing (meth)acrylate, and the fluorine-based (meth)acrylate are the same as described above for the adhesive film of the first embodiment.

In one embodiment, the hydroxyl group-containing (meth)acrylate is 5 parts by weight to 40 parts by weight, specifically 5 parts by weight to 30 parts by weight, 5 parts by weight to 20 parts by weight, 5 parts by weight to 15 parts by weight of the monomer mixture. , may be included in an amount of 8 parts by weight to 12 parts by weight. In the above range, peel strength and durability reliability of the adhesive film may be further improved. Specific types of the hydroxyl group-containing (meth)acrylate are as described above.

In one embodiment, the alkyl group-containing (meth)acrylate is 30 parts by weight to 85 parts by weight, 40 parts by weight to 80 parts by weight, 45 parts by weight to 80 parts by weight, 50 parts by weight to 85 parts by weight, 60 parts by weight of the monomer mixture. It may be included in an amount of 80 parts by weight to 80 parts by weight. In the above range, the bending reliability of the adhesive film may be good at low temperature and high temperature and high humidity. Specific types of the alkyl group-containing (meth)acrylate are as described above.

In one embodiment, the alkylene glycol group-containing (meth)acrylate is 2 parts by weight to 60 parts by weight, 5 parts by weight to 50 parts by weight, 10 parts by weight to 50 parts by weight, 10 parts by weight to 40 parts by weight of the monomer mixture. parts, 2 parts by weight to 15 parts by weight, 5 parts by weight to 15 parts by weight may be included. In the above range, stable and good foldability can be ensured even in a state in which the pressure-sensitive adhesive film is attached to an adherend having anti-fingerprint properties. Specific types of the alkylene glycol group-containing (meth)acrylate are as described above.

In one embodiment, the fluorine-based (meth)acrylate may be included in an amount of 0.05 parts by weight to 0.5 parts by weight, specifically 0.1 parts by weight to 0.5 parts by weight of the monomer mixture. In the above range, the pressure-sensitive adhesive film has a peel force of 25 gf/inch or more for an adherend having a fluorine-based anti-fingerprint layer formed at a water contact angle of 110° at 25° C. By maintaining the modulus detailed below at -20 °C, 25 °C and 80 °C, the foldability of the adhesive film can be secured in a wide temperature range, and there is no residue on the surface of the adherend when the adhesive film is released. Specific types of the fluorine-based (meth)acrylate are as described above.

In one embodiment, the (meth)acrylate having an alicyclic group may be included in an amount of 5 parts by weight to 20 parts by weight, specifically 7 parts by weight to 15 parts by weight of the monomer mixture. In the above range, it is possible to obtain the effect of increasing the peel force and the modulus of the pressure-sensitive adhesive film and secure the stable foldability of the pressure-sensitive adhesive film. Specific types of (meth)acrylate having an alicyclic group are as described above.

In one embodiment, the monomer mixture is 5 parts by weight to 30 parts by weight of the hydroxyl group-containing (meth)acrylate, 40 parts by weight to 80 parts by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group-containing (meth) It may include 5 parts by weight to 50 parts by weight of the acrylate, and 0.05 parts by weight to 0.5 parts by weight of the fluorine-based (meth)acrylate. Within the above range, there may be an effect of securing a peeling force to an adherend, good folding properties, and providing excellent durability.

In one embodiment, the monomer mixture is 5 parts by weight to 30 parts by weight of the hydroxyl group-containing (meth)acrylate, 40 parts by weight to 80 parts by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group-containing (meth) It may include 5 parts by weight to 50 parts by weight of the acrylate, 0.05 parts by weight to 0.5 parts by weight of the fluorine-based (meth)acrylate, and 5 parts by weight to 20 parts by weight of the (meth)acrylate having the alicyclic group. Within the above range, there may be an effect of securing a peeling force to an adherend, good folding properties, and providing excellent durability.

The monomer mixture may further include the above-mentioned comonomer.

The pressure-sensitive adhesive composition may further include the above-described initiator, crosslinking agent, and additives.

The initiator may be included in an amount of 0.0001 parts by weight to 5 parts by weight, specifically 0.001 parts by weight to 3 parts by weight, more specifically 0.001 parts by weight to 1 part by weight based on 100 parts by weight of the monomer mixture or the fluorine-based (meth)acrylic copolymer. . In the above range, the curing reaction may proceed completely, and a residual amount of the initiator may remain to prevent deterioration of the light transmittance of the pressure-sensitive adhesive film, and also it may lower the generation of bubbles and have excellent reactivity.

The crosslinking agent may be included in an amount of 0.001 parts by weight to 5 parts by weight, specifically 0.003 parts by weight to 3 parts by weight, specifically 0.005 parts by weight to 1 part by weight based on 100 parts by weight of the monomer mixture or the fluorine-based (meth)acrylic copolymer. In the above range, there is an effect of increasing excellent peel strength and reliability.

In one embodiment, the adhesive film may not include one or more of inorganic nanoparticles and organic nanoparticles.

Hereinafter, an optical member according to an embodiment of the present invention will be described.

The optical member includes an adhesive film and an optical film laminated on at least one surface of the adhesive film, and the adhesive film includes an adhesive film according to an embodiment of the present invention.

The optical film provides optical functions such as protection, polarization, optical compensation, display quality improvement, and/or conductivity among optical display devices, and may include an optical film driven by being attached to an adherend on which a fluorine-based anti-fingerprint layer is formed. . For example, the optical film is a protective film for a window film, a window film, a polarizing plate, a color filter, a retardation film, an elliptically polarizing film, a reflective polarizing film, an antireflection film, a compensation film, a brightness enhancing film, an alignment film, a light diffusion film, glass Transparent electrode film containing scattering prevention film, surface protection film, OLED device barrier layer, plastic LCD substrate, ITO, FTO (fluorinated tin oxide), AZO (aluminum dopped zinc oxide), CNT, Ag nanowire, graphene, etc. include The optical film may include an optical film used in a flexible display device.

Preferably, the optical member may include a protective film for a window film laminated on the upper surface of the adhesive film.

Referring to FIG. 1 , the optical member may include a protective film for a window film including a hard coating layer 110 and a base film 120 , and an adhesive film 200 . The adhesive film 200 includes an adhesive film according to an embodiment of the present invention. The optical member may be adhered to the window film on which the fluorine-based anti-fingerprint layer is formed through the adhesive film 200 to protect the window film.

The hard coating layer 110 is formed on one surface of the base film 120 and protects the window film. The hard coat layer may be formed of a composition for a hard coat layer including at least one of a UV curable resin, a UV curable oligomer, and a UV curable monomer, but is not limited thereto.

The base film 120 supports the adhesive film 200 and the hard coating layer 110 . The base film 120 may be a polyethylene terephthalate film or a thermoplastic polyurethane film.

Preferably, the optical member may include a protective film for a window film laminated on an upper surface of the adhesive film, and may include a window film on a lower surface of the adhesive film. The protective film for the window film may include a base film and a hard coating layer laminated on one surface of the base film. The window film may include a base film, a hard coating layer stacked on the base film, and an anti-fingerprint layer stacked on the upper surface of the hard coating layer.

The optical display device of the present invention may include the adhesive film of the present invention. The optical display device may include an organic light emitting device display device, a liquid crystal display device, and the like. The optical display device may include a flexible display device. However, the optical display device may include a non-flexible display device.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any sense.

Example One

As shown in Table 1 below, 100 parts by weight of a monomer mixture consisting of 2-ethylhexyl acrylate, 2-ethylhexyl diethylene glycol acrylate, 4-hydroxybutyl acrylate and isobornyl acrylate, and 0.05 parts by weight of the initiator Irgacure651 Mix well in the reactor. After exchanging dissolved oxygen in the reactor with nitrogen gas, the monomer mixture was partially polymerized by UV irradiation using a low pressure mercury lamp for several minutes to prepare a viscous liquid having a viscosity of 5,000 cps at 25°C. To the viscous liquid, 0.5 parts by weight of an initiator Irgacure651, 0.1 parts by weight of tridecafluorooctyl acrylate, and 0.01 parts by weight of dipentaerythritol hexaacrylate as a crosslinking agent were added and mixed to prepare a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition was applied to a PET (polyethylene terephthalate) film as a base film, and ^{an amount of light of 2,000 mJ/cm 2} was irradiated with ultraviolet rays to prepare an adhesive laminate of the pressure-sensitive adhesive film and the PET film.

Example 2 to Example 3

In Example 1, an adhesive film and an adhesive sheet of a PET film were prepared in the same manner as in Example 1, except that the configuration of the adhesive composition was changed as shown in Table 1 below.

Example 4

As shown in Table 1 below, 100 parts by weight of a mixture consisting of 2-ethylhexyl acrylate, 2-ethylhexyl diethylene glycol acrylate, 4-hydroxybutyl acrylate and isobornyl acrylate and tridecafluorooctyl acryl A monomer mixture for preparing a fluorine-based (meth)acrylic copolymer was prepared by mixing 0.1 parts by weight of the rate. To the monomer mixture, 0.05 parts by weight of the initiator Irgacure651 was mixed well in the reactor. After exchanging the dissolved oxygen in the reactor with nitrogen gas, the monomer mixture was partially polymerized by UV irradiation using a low pressure mercury lamp for several minutes to prepare a viscous liquid having a viscosity of 5,000 cps at 25°C. To the viscous liquid, 0.5 parts by weight of Irgacure651 as an initiator and 0.01 parts by weight of dipentaerythritol hexaacrylate as a crosslinking agent were added and mixed to prepare a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition was applied to a PET (polyethylene terephthalate) film as a base film, and ^{an amount of light of 2000 mJ/cm 2} was irradiated with ultraviolet rays to prepare an adhesive laminate of the pressure-sensitive adhesive film and the PET film.

comparative example One

An adhesive film and a PET film adhesive sheet were prepared in the same manner as in Example 1, except that 0.1 parts by weight of tridecafluorooctyl acrylate was not added in Example 1.

comparative example 2

An adhesive film and an adhesive sheet of a PET film were prepared in the same manner as in Example 3, except that 0.1 parts by weight of tridecafluorooctyl acrylate was not added in Example 3.

Comparative Example 3

In Example 1, 0.1 parts by weight of tridecafluorooctyl acrylate was not added and 0.1 parts by weight of a fluorine-based additive (one without a (meth)acrylate group) (F-569, DIC Corporation) was added. In the same manner, an adhesive film and an adhesive sheet of a PET film were prepared.

The physical properties of the adhesive films of Examples and Comparative Examples and the adhesive sheets of PET films were evaluated in Table 1 below, and the results are shown in Table 1 below.

(1) Modulus (G', unit: kPa): Using a rheometer (Anton Paar MCR-501), a dynamic viscoelasticity measuring device, the viscoelasticity was measured under auto strain conditions at a shear rate of 1 rad/sec and strain of 1%. measured. A plurality of adhesive films (thickness: 30 μm) prepared in Examples and Comparative Examples were laminated to prepare a sample having a thickness of 400 μm. The laminate was punched out with a perforator having a diameter of 8 mm and used as a specimen. Measurement was performed while increasing the temperature at a temperature increase rate of 5°C/min at a temperature of -60°C to 100°C in a state of applying a normal force of 3N to the specimen using a jig of 8 mm, -20°C, 25 The modulus was obtained at ℃ and 80℃.

(2) Peel strength (unit: gf/inch): The PET film was released from the adhesive sheet of Examples and Comparative Examples to obtain an adhesive film (thickness: 30 μm). The adhesive film was adhered to a thermoplastic polyurethane (TPU) film (seedom, thickness: 100 μm) and cut into a rectangular specimen (length x width: 100 mm x 25 mm). The rectangular specimen was laminated on a glass plate (length: 150 mm width: 100 mm x 25 mm) on which a fluorine-based anti-fingerprint layer (Secosa) having a water contact angle of 110 ° at 25 ° C was formed through the adhesive film. After the lamination, it was left at room temperature for 24 hours. Peeling force was measured when the rectangular specimen and the glass plate were peeled from the glass plate at a peeling angle of 180°, a peeling temperature of 25°C, and a peeling rate of 300 mm/min using a texture analyzer device (TA-XT). .

When measuring the peel force, the peel force was measured in the same manner as in Table 1, except that the water contact angle was changed as shown in Table 1 below instead of the glass plate having a fluorine-based anti-fingerprint layer having a water contact angle of 110° at 25°C.

(3) Creep (unit: %): PET film was released from the adhesive sheet of Examples and Comparative Examples to obtain an adhesive film (length 15 mm width x thickness: 15 mm x 15 mm x 30 µm). Creep was evaluated by using the obtained adhesive film to deform the adhesive with a certain force using TA-XT equipment and measuring the degree of deformation compared to before deformation.

(4) Characteristics of residue when releasing the adhesive film: When the peel force was measured in (2), the rectangular specimen and glass plate prepared in (2) were left at room temperature for 24 hours. It was evaluated whether there was any residue on the surface of the glass plate when the rectangular specimen was peeled from the glass plate. If there was no residue, it was evaluated as good, and if there was a residue, it was evaluated as bad.

(5) Folding properties: The prepared adhesive film and the adhesive sheet of the PET film were laminated on a PET base film having a fluorine-based anti-fingerprint layer (Secco) having a water contact angle of 110° through an adhesive film, and a rectangle (length x width) : 100mm x 25mm) to prepare a specimen for measuring foldability. The prepared specimen was folded in the direction of the anti-fingerprint layer of the specimen in a mold made with an interval of 2 mm, put so that the length of the specimen was 1/2, and stored at 25° C. for 72 hours. After 72 hours, when the specimen is removed from the mold and the folded part is visually checked, it is judged as good when no bubbles, folds, or lifting occur at all, and bad when it appears.

Example comparative example One 2 3 4 One 2 3 2-EHA 65 65 77 65 65 77 65 EHDG-AT 15 15 15 15 15 15 15 4-HBA 8 8 8 8 8 8 8 IBOA 12 12 0 12 12 0 12 TFA 0.1 0.5 0.1 0.1 0 0 0 initiator 0.5 0.5 0.5 0.5 0.5 0.5 0.5 crosslinking agent 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Fluorine-based additives 0 0 0 0 0 0 0.1 G' @-20℃ 128 128 109 130 129 108.5 127 @25℃ 27.2 26.8 25.1 27.1 27.9 24.8 28.2 @80℃ 13.9 14.0 11.2 13.8 14.1 11.1 13.5 peel force @110° 28.1 31.5 27.5 26.5 20.3 18.9 27.2 @102° 92 118 98 98 54 62 98 @95° 423 450 432 429 351 370 430 creep 415 399 652 402 390 667 450 residue properties Good Good Good Good Good Good error foldability Good Good Good Good Good Good Good

*2-EHA: 2-ethylhexyl acrylate (LG Chemical)

*EHDG-AT: 2-ethylhexyl diethylene glycol acrylate (EO (ethylene oxide group) 2 mol, Kyoeisha Chemical CO., LTD.)

*4-HBA: 4-hydroxybutyl acrylate (Mitsubishi chemical)

*IBOA: isobornyl acrylate (Osaka organic, homopolymer Tg: 94°C)

*TFA: Tridecafluorooctyl acrylate (DIC)

*Fluorine-based additives: (F-596, DIC)

As shown in Table 1, the adhesive film of the present invention has a high peeling force with respect to an adherend having a fluorine-based anti-fingerprint layer formed on the surface, and is easily removed when removed after being adhered to an adherend having a fluorine-based anti-fingerprint layer formed on the surface. and there was no adhesive residue on the surface of the adherend. In addition, the adhesive film of the present invention secured stable and good foldability even in a state in which it was adhered to an adherend having a fluorine-based anti-fingerprint layer formed on its surface.

On the other hand, Comparative Examples 1 to 3 in which the fluorine-based additive was not formed or had no (meth)acrylate group could not obtain all the effects of the present invention.

Simple modifications or changes of the present invention can be easily carried out by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (20)

A pressure-sensitive adhesive film formed of a pressure-sensitive adhesive composition comprising a (meth)acrylic copolymer and a fluorine-based (meth)acrylate or a pressure-sensitive adhesive composition comprising a fluorine-based (meth)acrylic copolymer,
The pressure-sensitive adhesive film has a peeling force of 25 gf/inch or more for an adherend formed with a fluorine-based anti-fingerprint layer having a water contact angle of 110° at 25° C.,
The adhesive film has a modulus ratio of -20°C modulus: 80°C modulus of 5:1 to 20:1,
The pressure-sensitive adhesive film has a modulus of 1 kPa to 100 kPa at 80 °C, the pressure-sensitive adhesive film.
The pressure-sensitive adhesive film of claim 1, wherein the pressure-sensitive adhesive film has a peel force of 25 gf/inch or more for an adherend having an anti-fingerprint layer having a water contact angle of 102° at 25°C.
The pressure-sensitive adhesive film of claim 1, wherein the pressure-sensitive adhesive film has a peel force of 25 gf/inch or more for an adherend having an anti-fingerprint layer having a water contact angle of 95° at 25°C.
According to claim 1, wherein the pressure-sensitive adhesive film is formed of a pressure-sensitive adhesive composition comprising the (meth) acrylic copolymer and fluorine-based (meth) acrylate,
The (meth)acrylic copolymer is formed of a monomer mixture comprising a hydroxyl group-containing (meth)acrylate, an alkyl group-containing (meth)acrylate and an alkylene glycol group-containing (meth)acrylate, the adhesive film.
According to claim 4, wherein the fluorine-based (meth) acrylate will be included in an amount of 0.05 parts by weight to 0.5 parts by weight based on 100 parts by weight of the monomer mixture, the pressure-sensitive adhesive film.
The pressure-sensitive adhesive film according to claim 4, wherein the alkylene glycol group-containing (meth)acrylate is included in an amount of 10% to 50% by weight of the monomer mixture.
According to claim 4, wherein the monomer mixture is 5% to 30% by weight of the hydroxyl group-containing (meth)acrylate, 40% to 80% by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group-containing (meth) ) A pressure-sensitive adhesive film comprising 5% to 50% by weight of an acrylate.
According to claim 4, wherein the fluorine-based (meth) acrylate is a perfluorinated (perfluorinated) monofunctional (meth) acrylate having an alkyl group having 1 to 10 carbon atoms substituted with an alkyl group having 1 to 10 carbon atoms. that, the adhesive film.
According to claim 8, wherein the fluorine-based (meth) acrylate is tridecafluorooctyl (meth) acrylate, dodecafluoroheptyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate at least one kind That comprising a, the pressure-sensitive adhesive film.
The adhesive film of claim 4, wherein the monomer mixture further comprises (meth)acrylate having an alicyclic group.
11. The method of claim 10, wherein the monomer mixture is 5% to 30% by weight of the hydroxyl group-containing (meth)acrylate, 40% to 80% by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group-containing (meth) ) An adhesive film comprising 5 wt% to 50 wt% of an acrylate and 5 wt% to 20 wt% of a (meth)acrylate having the alicyclic group.
According to claim 1, wherein the pressure-sensitive adhesive film is formed of a pressure-sensitive adhesive composition comprising the fluorine-based (meth) acrylic copolymer,
The fluorine-based (meth)acrylic copolymer is a copolymer of a monomer mixture comprising a hydroxyl group-containing (meth)acrylate, an alkyl group-containing (meth)acrylate, an alkylene glycol group-containing (meth)acrylate, and a fluorine-based (meth)acrylate that, the adhesive film.
According to claim 12, wherein the monomer mixture is 5 to 40 parts by weight of the hydroxyl group-containing (meth)acrylate, 30 to 85 parts by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group-containing (meth) ) An adhesive film comprising 2 parts by weight to 60 parts by weight of an acrylate, 0.05 parts by weight to 0.5 parts by weight of the fluorine-based (meth)acrylate.
According to claim 12, wherein the fluorine-based (meth) acrylate is a perfluorinated (perfluorinated) monofunctional (meth) acrylate having an alkyl group having 1 to 10 carbon atoms, substituted with an alkyl group having 1 to 10 carbon atoms. that, the adhesive film.
15. The method of claim 14, wherein the fluorine-based (meth) acrylate is tridecafluorooctyl (meth) acrylate, dodecafluoroheptyl (meth) acrylate, heptadecafluorodecyl (meth) at least one kind of acrylate That comprising a, the pressure-sensitive adhesive film.
The pressure-sensitive adhesive film of claim 12, wherein the monomer mixture further comprises (meth)acrylate having an alicyclic group.
The method of claim 16, wherein the monomer mixture is 5 to 30 parts by weight of the hydroxyl group-containing (meth)acrylate, 40 to 80 parts by weight of the alkyl group-containing (meth)acrylate, and the alkylene glycol group-containing (meth) ) 5 parts by weight to 50 parts by weight of the acrylate, 0.05 parts by weight to 0.5 parts by weight of the fluorine-based (meth)acrylate, and 5 parts by weight to 20 parts by weight of the (meth)acrylate having an alicyclic group, the adhesive film .
delete Comprising an optical film laminated on at least one surface of the adhesive film and the adhesive film,
The adhesive film is an optical member comprising the adhesive film of any one of claims 1 to 17.
The optical display device comprising the adhesive film of any one of claims 1 to 17.

Images